Approach to the management of Hypertension

HYPERTENSION CONSENSUS COMMITTEE
WORKING GROUP



 

Chairman: 
Dr Zaki Morad b Mohd Zaher  
Consultant Nephrologist  
Department of Nephrology  
Hospital Kuala Lumpur  
Kuala Lumpur
Secretary: 
Dr. Philip N. Jeremiah 
Consultant Nephrologist  
Department of Nephrology  
Hospital Kuala Lumpur  
Kuala Lumpur 

Panelists:

Dr. Abdul Rashid b A Rahman  
Assoc. Prof. 
Clinical Pharmacologist  
Department of Pharmacology & Medicine  
Universiti Sains Malaysia  
Kubang Kerian, Kelantan 
 
 
 
Dr. Khoo Kah Lin 
Consultant Cardiologist 
Consultant Physician/ Pantai Medical Centre 
Kuala Lumpur 
 
 
Dato’ Dr Robaayah Zambahari  
Consultant Cardiologist  
Department of Cardiology  
Institute Jantung Negara  
Kuala Lumpur
 
 
 
Dr. Khalid Yusof 
Professor of Medicine & 
Consultant Cardiologist 
University Kebangsaan Malaysia 
Cheras
Dr Chua Chin Teong 
Assoc. Prof. & Consultant Nephrologist  
Division of Nephrology 
Department of Medicine 
University Hospital 
Kuala Lumpur
  
 
 
Dr Guna Segaran 
Consultant Obstetrician & Gynaecologist 
Damansara Specialist Hospital 
Petaling Jaya
Dr Chia Yook Chin 
Assoc. Prof. & Consultant Physician Department of Primary Care Medicine 
University Hospital 
Kuala Lumpur 
Dr Lim Yam Ngo 
Consultant Paediatric Nephrologist 
Institute of Paediatrics 
Hospital Kuala Lumpur 
Kuala Lumpur
Dr Fan Kin Sing 
Consultant Nephrologist 
Gleneagles Intan Medical Centre 
Kuala Lumpur
Dr. Shanker V. Moorthy 
Senior Registrar in Cardiology 
Department of Cardiology 
Institute Jantung Negara 
Kuala Lumpur

 



Contents

Introduction
Definition & Classification of High Blood Pressure
Measurement of blood pressure
Diagnosis and Assessment
Management
Hypertension in Special Groups
        Hypertension in patients with diabetes mellitus
        Hypertension in patients with coexisting Cardiovascular Diseases (CVD)
        Hypertension in pregnancy
        Hypertension in the paediatric patient
        Hypertension in the Elderly
 
Graphics

Figure 1: Distribution of diastolic blood pressure in a Western population
Figure 2: Changes in blood pressure with age in three different communities: London, urban Zulu and
               Kalahari Bushmen
Figure 3: Management of a patient with hypertension
Table 1: Classification of Blood Pressure for Adults Aged 18 Years and older
Table 2: Manifestations of target organ damage
Table 3: Efficacy of Non-Pharmacological Management
Table 4: Antihypertensives currently available in Malaysia
Table 5: Choice of Anti-Hypertensive drugs in patients with concomitant disease
Table 6: Effective anti-hypertensive combinations
Table 7: Oral Treatment for Hypertensive  Urgencies
Table 8: Treatment Options for  Hypertensive Emergencies
Table 9: Blood  Pressure Levels  for the 90th and 95th Percentiles of Blood Pressure for Boys Aged
              I to 17 Year  by Percentiles of Height
Table 10: Blood Pressure Levels  for the 90th and 95th Percentiles  of  Blood Pressure for Girls Aged 1
                to 17 Years by Percentiles of Height
Table 11: Antihypertensive Drugs for Therapy of Chronic Hypertension in Children
Table 12: Antihypertensive Drug Therapy for Hypertensive Emergencies in Children

Appendix

Introduction

The prevalence of hypertension in the adult population found at screening ranges from 15-25%. In Malaysia a recent survey ( the National Health and Morbidity Survey II ) indicated a prevalence of 24%. The figure below shows the distribution of systolic and diastolic blood pressure in the Malaysian population aged 30 years and above.

Patients with hypertension are at risk of cardiovascular diseases. Control of elevated blood pressure has contributed to reduction in morbidity and mortality from stroke and coronary heart disease. The prevention and treatment of hypertension therefore is an important public health challenge.

The management of hypertension has widened over the years from a structured step wise approach to one of the individualisation of treatment. The increasing availability of drugs of different classes and duration of action facilitates this approach. There is also greater recognition of non- pharmacological treatment.

There is currently no consensus or practice guidelines on the management o hypertension in this country. The Ministry of Health and the Academy of Medicine formed a working group to draw up a practice guideline on the management of hypertension.The group consists of representatives from different specialities including family medicine. In preparing this document the group relied on a number of existing guidelines from USA and Europe and on many other published studies. Where possible the guideline is evidence based. The guidelines have been presented to practitioners and their comments have been incorporated where relevant in this document.

Distribution of Diastolic and Systolic Blood Pressure in Malaysian Adult Population age > 30 yrs

Definition & Classification of High Blood Pressure

Blood pressure in the general population is a continuum. The distinction between normotension and hypertension is based on epidemiological observation. In a general population, the distribution of blood pressure follows a Gaussian distribution as shown in Figure 1.
 

Figure 1: Distribution of diastolic blood pressure in a Western population

  1. Adopted from Souhami RL, Moxham J. Textbook of Medicine 2 nd edition 1994 p.429 - 438

Blood pressure also varies with age, with an increasing trend in systolic and diastolic blood pressure with increasing age, as illustrated in Figure 2.

Figure 2: Changes in blood pressure with age in three different communities: London, urban Zulu and Kalahari Bushmen

  1. Adopted from Souhami RL, Moxham J. Textbook of Medicine 2 nd edition 1994 p.429 - 438

The definition of hypertension has been reviewed by various authorities, including the World Health Organisation/ International Society of Hypertension (WHO/ISH) and The Joint National Committee on the Detection, Evaluation and Treatment of High Blood Pressure (JNC). The definition and classification of high blood pressure is illustrated in  Table 1 and is adopted from the Fifth Report of the JNC.
 
 

Table 1. Classification of Blood Pressure for Adults Aged 18 Years and Older
Category Systolic, mmHg Diastolic, mmHg
Normal <130 <85
High Normal 130 - 139 85 - 89
Hypertension:    

Stage 1 (mild)

140 - 159 90 - 99

Stage 2 (moderate)

160 - 179 100 - 109

Stage 3 ( severe)

180 - 209 110 - 119

Stage 4 (very severe)

>210 >120

Adopted from The Fifth Report of the Joint National Committee on Detection, Evaluation, and treatment of High blood Preassure (JNC V). Arch Intern Med 1993; 153:.154 - 183

The above table provides a new classification of adult blood pressure based on impact on risk. The traditional terms mild and moderate hypertension failed to convey the major impact of high blood pressure on risk of cardiovascular diseases (CVD). High-normal blood pressure is included as a category because persons with systolic blood pressure (SBP) and/or diastolic blood pressure (DBP) in these ranges are at increased risk of developing definite high blood pressure, and of experiencing non-fatal and fatal cardiovascular events, compared with otherwise similar persons with lower blood pressures. Individuals with high-normal blood pressure should be monitored yearly and counselled in regard to life-style modifications that can reduce their blood pressure; pharmacological treatment is rarely if ever needed.

All stages of hypertension are associated with increased risk of non-fatal and fatal CVD events, stroke and renal disease. The higher the blood pressure, the greater is the risk. Stage 1 Hypertension is the commonest form of high blood pressure in the adult population and is responsible for a large proportion of the morbidity and mortality associated with hypertension. All stages of hypertension warrant effective long term therapy.

Isolated systolic hypertension

This has been defined by the WHO/ISH as a SBP greater than 140 mmHg with the DBP less than 90 mmHg. Isolated systolic hypertension is common in the elderly (6-10% of individuals aged 65-74 years) and is associated with increased morbidity and mortality. Pharmacological treatment has been shown to confer benefit.

Isolated systolic hypertension may also be found in adolescents and young adults. There is no evidence particularly in the adolescents that it should be treated other than with life-style modifications. In adults < 65 years of age, although there is little direct evidence of benefit from treating isolated systolic hypertension it seems reasonable to consider drug therapy in subjects with SBP at or above 160mmHg.
 

White coat hypertension

White coat hypertension or effect is a condition in which blood pressure is elevated in the presence of a medical personnel but falls when the subject leaves the medical environment. White coat hypertension accounts for about 20% of hypertensives. There is increasing evidence that damage to target organ correlates better with out-of-office measurements including those with ambulatory blood preassure monitoring than with office measurements. However, current gudelines and major clinical trials are based on clinic measurements.

References :

1. Souhami RL, Moxham J. Textbook of Medicine 2 nd edition 1994 p.429 - 438

2. The Fifth Report of the Joint National Committee on Detection, Evaluation, and
    treatment of High blood Preassure (JNC V). Arch Intern Med 1993; 153:.154 - 183

3. Guidelines for the management of mild hypertension: memorandum from a World Health
    Organization/International Society of Hypertension meeting. Journal of Hhypertension 1993; 11: 905-
    91

4. Weber MA. Ambulatory blood pressure monitoring: clinical uses. Hosp Prac 1992; 117-28
 

Measurement of blood pressure

The measurement of blood pressure should be done correctly. Blood pressure can be measured directly or indirectly. There are three common devices used for the indirect measurement of blood pressure namely:

There are many calibrated electronic or ambulatory blood pressure devices available in the market. If any are to be used , only professionally accredited models that are properly maintained should be considered. However, mercury sphygmomanometer remains the gold standard for measurement.

The mercury column

The mercury meniscus should be at zero.

The sphygmomanometer cuff

Both the length and width of the inflatable bladder are critical. The bladder (length) should encircle at least 80% of the circumference of the arm whilst the width should at least be 40% of the circumference.

The sphygmomanometer inflation-deflation device

It is important to ensure that inflation-deflation device functions properly. The following may indicate malfunction of the device:

Auscultatory measurement of systolic and diastolic pressures

The following technique is recommended for the measurement of blood pressure using a sphygmomanometer :

In some groups e.g. pregnant women, anaemic or elderly patients the sounds may continue until the zero point. In such instances the muffling of the repetitive sounds (Korotkoff Phase IV) is taken as the diastolic pressure. The point of muffling is usually higher than the true arterial diastolic pressure. If Korotkoff Phase IV is used, this should be clearly recorded.

The blood pressure should be measured in both arms. If the difference in blood pressure between the two arms is > 20/10 mmHg , then there maybe an arterial anomaly which requires further evaluation.

The blood pressure should be taken both lying and at least one minute after standing to detect any postural drop.

Ambulatory blood pressure monitoring

Ambulatory blood pressure monitoring is not necessary for the diagnosis and management of most patients with hypertension but this technique has certain usefulness in selected research and clinical situations. These include:

References :

1. O' Brien ET, Beevers DG, Marshall HJ. ABC of Hypertension (3rd edition)

2. Petrie JC, O 'Brien ET, Littler WA, De Swiet M: British Hypertension Society - Recommendations
    on Blood Pressure Measurement ; 1986, 293; 611-615

3. The Fifth Report of the Joint National Committee on Detection, Evaluation and Treatment of High
    Blood Pressure : Arch. Intern. Med. - 1993, 153:154-184

4. National High Blood Pressure Education Programme Working Group Report on Ambulatory Blood
    Pressure Monitoring : Arch. Intern. Med.- 1990, 150: 2270-2280

5. Summary of 1993 World Health Organisation -International Society of Hypertension guidelines for the
    management of mild hypertension : BMJ ,1993, 307: 1541-1546

6. Management guidelines in essential hypertension: report of the second working party of the British
    Hypertension Society : BMJ ,1993, 306 : 983-987

Diagnosis and Assessment

Hypertension should not be diagnosed on the basis of a single measurement unless there is target organ damage (TOD) or SBP = 210 mm Hg or DBP = 120 mm Hg. Otherwise, the initial elevated readings should be confirmed on at least two subsequent visits. The reevaluation may be done within days or weeks depending upon the level of the initial blood preassure.

The objectives of evaluating a newly diagnosed hypertensive patient should be to search for curable causes, define target organ status and look for other atherogenic risk factors.

A complete history should be taken. Symptoms of TOD as well as concomitant conditions that increase morbidity and mortality such as diabetes, obesity, hyperlipidemia should be noted. A history of smoking, alcohol and sodium intake is also relevant. In the family history, attention should be paid to the presence of hypertension, diabetes, hyperlipidaemia, ischaemic heart disease and stroke.

Secondary causes of hypertension should excluded. These include renal parenchymal disease, endocrine disorders, coarctation of the aorta and renovascular hypertension. A history of intake of oral contraceptives, non-steroidal anti-inflammatory agents, steroids, nasal decongestants and liquorice should be enquired.

Physical examination should aim at assessing TOD, excluding secondary causes of hypertension and identifying concomitant risk factors. These include:
 

General examination including height and weight 
Blood pressure measurement
Radio-femoral delay
Carotid bruit, renal artery bruit and peripheral pulses
Cardiac examination
Respiratory examination
Abdominal masses eg polycystic kidneys
Fundoscopy

 
The initial work-up should include the following investigations:

If the examination or investigations suggest a secondary cause, the patient should be referred for specialist evaluation. If there is TOD (Table 2), further tests should be done to evaluate the severity.

Table 2 Manifestations of target organ damage
 

Organ System  Manifestations
Cardiac Left ventricular hypertrophy, coronary artery disease, heart failure.
Cerebrovascular Transient ischemic attack or stroke.
Peripheral vascular Absence of 1 or more major pulses in extremities (except for dorsalis pedis) with or without intermittent claudication ; aneurysm.
Renal  Raised serum creatinine; microalbuminuria, proteinuria (1+ or greater),
Retinopathy Hemorrhages or exudates, with or without papilloedema.

Adopted from The Fifth Report of the Joint National Committee on Detection, Evaluation, and treatment of High blood Preassure (JNC V). Arch Intern Med 1993; 153:.154 - 183

References

1. Guidelines for the management of mild hypertension: Memorandum from a World Health
    Organization/ International Society of Hypertension meeting. Journal of Hypertension 1993,
    11:905-918

2. Management guidelines in essential hypertension: report of the second working party of the British
    Hypertension Society. BMJ 1993, Vol. 306: p983-987

3. The Fifth Report of the Joint National Committee on Detection, Evaluation, and Treatment of High
    Blood Pressure (JNC V). Arch Intern Med., 1993 Vol. 153 pg 154-183

Management

The goal of treatment in patients with hypertension is to prevent morbidity and mortality associated with high blood pressure by the least intrusive means possible. This can be to a large extent accomplished by achieving and maintaining SBP < 140 mmHg and DBP < 90 mmHg with the most cost effective means while maintaining good quality of life. Treatment of blood pressure encompasses non-pharmacological and pharmacological measures. As with all chronic diseases, patient education plays a vital role in ensuring compliance.

Non-Pharmacological Management

Non-pharmacological management plays an important part in the treatment of elevated blood pressure. It involves life style modifications and should be advised to all patients with hypertension. It may be the only treatment necessary in Stage I hypertension and can reduce blood pressure by an average of 10/8 mm Hg (Table 3).

Non-pharmacological management includes:

Weight reduction

Weight reduction is most beneficial in patients who are more than 10% overweight.

As far as possible, aim for ideal Body Mass Index (BMI) of 20-25 kg/m2. BMI is calculated as the weight in kilograms divided by the square of the height in metres. However, even a 5% reduction in weight will result in significant lowering of blood pressure.

Avoidance of excessive alcohol intake

The intake should not exceed 21 units per week for men and 14 units per week for women. One unit of alcohol is equivalent to 1/2 a pint of beer or 100 mls. of wine or 20 mls. of proof whisky.

Sodium intake

Elderly people are more sensitive to sodium intake. An intake < 100 mmol or 6g sodium chloride a day (equivalent to 3 teaspoonfuls of salt or 8 teaspoonfuls of monosodium glutamate) is recommended.

Regular physical exercise

Dynamic isotonic exercise (e.g. walking) is more effective than static isometric exercise (e.g. weightlifting). "Milder" exercise like brisk walking for 30-60 minutes 3-5 times a week are preferred.

Cessation of smoking

This is important in the overall management of the hypertensive patient in reducing cardiovascular risk.

Reduction of cholesterol and saturated fat intake

As with smoking, this is important in reducing cardiovascular risk.

Other non-pharmacological management include stress management, micronutrient alterations and dietary supplementation with fish oil, potassium, calcium, magnesium and fibre. However, they have limited or unproven efficacy

 Table 3: Efficacy of Non-Pharmacological Management
 

Treatment Intervention BP Reduction (mmHg)
Sodium restriction Dietary advice  

Sodium intake (<100mmol/day)

8-15 systolic 

5- 6 diastolic

Relaxation Relaxation Techniques 9-27 systolic 

4-16 diastolic

Weight loss Diet and Exercise 9-27 mean arterial pressure
Exercise Aerobic Exercise Programme 6-13 systolic 

9-12 diastolic

General Guidelines to the pharmacological treatment of hypertension

There are many drugs available for the treatment of hypertension. The ideal drug must not only be efficacious and free from side-effects, it must also be able to prevent all the complications of hypertension, besides being easy to use and at an affordable cost. Reduction in blood pressure of upto 18/12 mmHg may be expected from a single drug therapy. It may not matter which drug is used, it is the reduction of blood pressure which provides the main benefit. Table 4 shows the drugs currently available in Malaysia.
 

Table 4. Antihypertensives currently available in Malaysia
 

Diuretics 

Hydrochlorothiazide 
Amiloride-Hydrochlorothiazide 
Chlorthalidone 
Triamterene-hydrochlorothiazide 
Methyclothiazide 
Bumetanide 
Frusemide 
Indapamide 
Chlorothiazide 

Beta blockers 

Atenolol 
Metoprolol 
Propranolol 
Nadolol 
Pindolol 
Tertatolol 
Timolol 
Bisoprolol 
Betaxolol 
Acebutolol 
Sotalol 
Oxprenolol 

  

 

Calcium Channel blockers 

Nifedipine 
Nicardipine 
Isradipine 
Nilvadipine 
Felodipine 
Amlodipine 
Lacidipine 
Diltiazem 
Verapamil 

Combined alpha/beta 
blockers 

Labetolol 
Carvedilol 

Direct vasodilators 

Minoxidil 
Hydralazine 
Sodium Nitroprusside 
Nitroglycerin 

Combination drug 

Atenolol/chlorthalidone 
Oxprenolol/chlorthalidone 
Pindolol/clopamide

ACE Inhibitors 

Captopril 
Enalapril 
Lisinopril 
Perindopril 
Quinapril 
Ramipril 
Fosinopril 
Delapril 
Cilazapril 

Alpha blockers 

Prazosin 
Terazosin 
Doxazosin 

Centrally acting drugs 
Methyldopa 
Clonidine 
Reserpine 
 
 

Angiotensin II antagonist 

Losartan

(DIMS Vol. 26; 2 1997)

For patients with Stage I hypertension, a period of 3 to 6 months of observation is recommended unless target organ involvement is already evident. During this period, appropriate advice should be given on life-style modifications. Follow-up at this juncture should be about 2 monthly so that there will be between 1 to 3 visits over the period. Efficacy of the above intervention should be assessed. Figure 3 outlines the management of a patient with hypertension.

In patients with Stage I and Stage II hypertension, treatment should be started with monotherapy. The key word is ‘individualise’. Ideally ‘individualisation’ should be based on scientific evidence of reduction in endpoints. Otherwise, theoretical benefits may determine the choice of drugs (See Appendix). The choice of drugs will also be determined by the presence of concomitant diseases. Also important are contraindications to the use of some drugs (Table 5). In patients with no concomitant diseases, a diuretic or a beta blocker should be chosen because numerous randomised control trials have shown that they reduce morbidity and mortality.

Table 5: Choice of Anti-Hypertensive drugs in patients with concomitant disease
 

Concomitant 
Disease
Diuretics Beta-blockers ACE inhibitors Calcium channel blockers Peripheral alpha1-blockers Angiotensin II antagonists      
Diabetes mellitus care needed care needed yes * yes yes yes      
Gout No yes  yes yes yes yes/no      
Dyslipidaemia care needed care needed yes yes yes yes      
Ischaemic heart  

Disease

yes yes * yes yes yes yes      
Heart failure yes care needed yes* care needed yes yes      
Asthma yes  no yes yes yes yes      
Peripheral vascular disease yes care needed yes yes yes yes      
Renal impairment yes yes care 

needed

yes yes care 

needed

     
Renal artery stenosis yes yes care needed yes yes care needed      
Elderly with no co-morbid conditions yes* yes* yes yes* yes yes      

* Drug of choice, (please refer to appendix)

It is important to remember that following initiation of treatment with monotherapy, target blood pressure can only be achieved in 50 - 60 % of patients. If after a sufficient period of treatment (upto 6 weeks) BP is still not controlled, three options are available:

Table 6: Effective anti-hypertensive combinations
 

Effective combinations Advantages
Beta blockers + diuretics Cheap, beneficial in the elderly
Beta blockers + calcium channel blockers Relatively cheap, appropriate for concurrent 
ischaemic heart disease
Calcium channel blockers + ACE inhibitors Appropriate for concurrent dyslipidaemias and diabetes mellitus. May be expensive.
ACE inhibitors + diuretics Appropriate for concurrent heart failure.

 

Efforts must be made to reach target blood pressure. For patients less than 65 yrs old, target BP should be < 140/90 mmHg and lower for diabetics (BP < 130/85 mmHg). For elderly patients > 65yrs old target BP is < 160/90 mmHg and should be lower for diabetics . In general once blood pressure is controlled, most patients will require life long treatment. If BP is still > 160/90 mmHg with three drugs at appropriate dosage, patients by definition have resistant hypertension. A quick check on the possible causes of resistant hypertension is required. These include :

In Malaysia, a study has shown that the commonest cause of ‘resistant hypertension’ requiring admission is non-compliance.


Follow-up visits

Patients with Stage I hypertension without TOD should generally be seen within 1 to 2 months after the initiation of therapy to determine the adequacy of blood pressure control, and the presence of adverse effects. The choice of drugs and associated medical problems including TOD, other major risk factors and laboratory test abnormalaties will also play a part in determining the frequency of patient follow-up. Once blood preassure is stabilized, follow-up at 3 - 6 month intervals is generally appropriate.

When to refer

Although most patients can be effectively managed by their own family practitioners, patients with the following conditions should be referred to the appropriate specialist for further assessment:

Management of Stage IV (Very Severe) Hypertension

Stage IV hypertension is defined as SBP = 210 and/or DBP = 120 mmHg. These patients may present in the following manner:

Management of these patients depends on the clinical presentation and laboratory investigations. The evaluation of these patients is as in any other patients with hypertension including examination of peripheral pulses, fundoscopy and urinalysis. Further investigations to look for secondary hypertension are warranted.

After this initial assessment, patients can then be categorised accordingly. These are:

a) severe asymptomatic hypertension

b) hypertensive urgency

c) hypertensive emergency

(b ) and (c) are also referred to as "hypertensive crises".

Specific Management

a) Severe asymptomatic hypertension

Admission may be necessary in those who are newly diagnosed or where non-compliance is suspected. Patients already on treatment need to be reviewed and appropriate measures taken which include optimising treatment by using effective combination therapy.

b) Hypertensive Urgencies

These include patients with grade III and IV retinal changes , proteinuria and symptoms which may suggest organ failure. These patients need to be admitted. Blood pressure measurement should be repeated after 30 minutes of bed rest. Initial treatment should aim for about 25% reduction in blood pressure over 24 hours. Oral drugs shown to be effective in clinical trials are as in Table 7. Combination therapy is often necessary. This does not necessarily mean that these drugs should be routinely used in all cases of hypertensive urgencies.

Table 7 : Oral Treatment for Hypertensive Urgencies
 

Drug Dose (mg)

Onset of action (hr)

Duration of action (hr)

Frequency (prn)
Captopril 

Nifedipine 

Labetalol 

Clonidine

 25 

10-20  

200-400  

0.1-0.2 

0.5 

0.5 

2.0 

2.0

6 

3-5 

6 

> 6

1-2 hrs 

1-2 hrs 

4 hrs 

2 hrs

 

c) Hypertensive Emergencies

These are complications of severe hypertension such as acute left ventricular failure, dissecting aneurysm, acute coronary syndromes, hypertensive encephalopathy, subarachnoid haemorrhage, haemorrhagic stroke, acute renal failure and eclampsia.

All these patients must be admitted. The blood pressure needs to be reduced relatively quickly. It is generally suggested that the BP be reduced by 25% over 3 to12 hours. This is best achieved with parenteral drugs (Table 8).

Table 8: Treatment Options for Hypertensive Emergencies
 

Drugs Dose Onset of action Duration Remarks
Sodium nitroprusside 

Labetalol 
 
 
 

Nitrates 
 
 
 
 

Hydralazine

0.25- m gkg/min 
 

IV bolus 50-200 mg then  
2mg/min 
 

5-100 m g/min 
 
 
 
 

I 
V 10-20 mg 
IM 10-50 mg

10 seconds 
 

< 5 min 
 
 
 

2-5 min 
 
 
 
 

10-20 min 
20-30 min

1-5 min 
 

3-6 hrs 
 
 
 

3-5 min 
 
 
 
 

3-8 hrs

Caution in renal failure 

Caution in heart failure 
 
 

Preferred in acute coronary syndromes and acute pulmonary oedema 

Caution in acute coronary syndromes, cerebrovascular accidents and disecting aneurysm

 
Dangers of rapid reduction in blood pressure

Rapid reduction of BP in asymptomatic severe hypertension or hypertensive urgency is best avoided. Oral or sublingual drugs with rapid onset of action can result in an uncontrolled drop in blood pressure leading to stroke, myocardial ischaemia and even death. Several serious side effects have been reported with the administration of sublingual fast-acting nifedipine. Therefore, its routine use to lower blood pressure rapidly in the general adult population is to be discouraged.

References

1. Editorial,Thought for autoregulation in the hypertensive patient. Lancet 1979 Sept. 8 10.

2. Garcia J, Vidt D: Current management of Hypertensive Emergencies. Drugs 1987; 34:263 - 278

3. Editorial, Severe symptomless hypertension. Lancet 1989 Dec. 9 1369 - 1370

4. Calhoun D, Oparil S: Treatment of hypertensive crisis. NEJM 1990, 323(17):1177 - 1182

5. Editorial, Hypertensive Emergencies. Lancet 1991; 338: 220 - 221

6. Messerli F, Kowey P, Grodzicki T: Sublingnal nifedipine for hypertensive emergencies. Lancet 1991;
    338 : 881 (letter to Editor)

7. Kennedy M: Risks versus benefits in cardiovascular therapy. Adverse Drug Reaction Bulletin 1992,
   156 : 587 - 590

8. Kaplan N: Management of hypertensive emergencies. Lancet 1994; 344 : 1335 - 1338

9. O’Connell J, Gray C: Treating hypertension after stroke. BMJ 1994, 308 : 1523 - 1524

10. Calhoun D, Oparil S: (Editorial) Hypertensive crisis after FDR - a partial victory. NEJM 1995;332 :
     1029 - 1030

11. Isles CG: Management of hypertensive crises. Scott. Med. J 1995; 40 : 23 - 25

12. Rahman ARA, Hassan Y, Abdullah I. Admissions for severe hypertension; who and why.
      Proceedings of the First Pacific Rim Hypertension Conference Tokyo Japan 1995

13. Burnier M, Waeber B, Brunner HR. First-line pharmacological treatment of hypertension. Journal of
      Internal Medicine. 1992;232:381-388

14. Opie LH. Individualised selection of antihypertensive therapy. Drugs. 1993 (Suppl. 2) 142-148

15. Collins R & MacMahon S. Blood pressure: antihypertensive drug treatment and risks of stroke and
      of  coronary heart disease. British Medical Bulletin 1994; 50(2): 272-298

16. Freis FD & Papademetriou. Current drug treatment. Patterns with antihypertensive drugs. Drugs
     1996;52(1):1-16

17. Gong L, Zhang W, Zhu Y et al. Shanghai trial on nifedepine in the elderly (STONE). Journal of
      Hypertension 1996;14:1237-1245.
 

Hypertension in Special Groups

Hypertension in patients with diabetes mellitus

Hypertension is a common problem in patients with diabetes mellitus. Its presence increases the risk of morbidity and mortality. In insulin-dependent diabetes (IDDM), the incidence of hypertension rises from 5% at 10 years to 33% at 20 years and 70% at 40 years, and appears to be closely related to diabetic renal disease. In non-insulin dependent diabetes (NIDDM), hypertension is even more prevalent. The Hypertension in Diabetes Study Group reported a 39% prevalence of hypertension among newly diagnosed patients, and in approximately half of them the elevated blood pressure predated the onset of microalbuminuria and was strongly associated with obesity.

Treatment

Hypertension should be detected and treated early in the course of diabetes mellitus to prevent cardiovascular disease and to minimise the rate of progression of renal disease and diabetic retinopathy. The approach to the treatment of hypertension in diabetes should be very much along the guidelines for treatment of hypertension in general. Nonetheless, a few important issues concerning non-pharmacological management and drug treatment need to be highlighted.

Non-pharmacological management

This cannot be overemphasised. Dietary counselling should target at optimal body weight and take into consideration glycaemic control and the management of concomitant dyslipidaemia.

Moderate dietary sodium restriction is advisable. Further sodium restriction, with or without a diuretic, may be necessary in the presence of nephropathy or when the blood pressure is difficult to control.

Pharmacological Management

The use of certain classes of antihypertensive drugs (Table 5) may disadvantage the diabetic patient by virtue of their modes of action or adverse effects. Diabetic control may be compromised and various diabetic complications aggravated.

Target blood pressure

Blood pressure tends to be higher in diabetics compared with normal subjects even within the "normal range". There are suggestions that a lower target blood pressure may be necessary to maximally protect against the development and progression of diabetic renal disease. In general, the SBP should be targeted to < 130 mmHg and DBP < 85 mmHg.

References

1. Bakris GL et al. Treatment of arterial hypertension in diabetic humans: Importance of therapeutic
    selection. Kidney Int 1992; 41:912

2. Epstein M et al. Diabets mellitus and hypertension. Hypertension 1992; 19:403

3. Kasiske BL et al Effect of antihypertensive therapy on the kidney in patients with diabetes mellitus.
   Ann Int Med 1993; 118:129

4. Lewis EJ et al The effect of angiotensin-converting -enzyme inhibition on diabetic nephropahty. N Engl
   J Med 1993; 329:1456

5. Lind L et al Long-term metabolic effects of antihypertensive drugs. Am Heart J 1994; 128:1177

6. Mogensen CE Long-term antihypertensive treatment inhibiting progression of diabetic nephropathy. Br
    Med J 1982; 285:685

7. The Hypertension in Diabetes Study Group. Hypertension in Diabetes Study (HDS) I. Prevalence of
    hypertension in newly presenting type 2 diabetic patients and the association with risk factors for
    cardiovascular and diabetic complications; II. Increased risk of cardiovascular complications in
    hypertensive type 2 diabetic patiens. J Hypertens 1993; 11:309, 319

8. The National High Blood Pressure Education Program Working Group. National High Blood Pressure
    Education Program Working Group report on hypertension in diabetes mellitus. Hypertension 1994;
    23:145

9. Tjoa HI et al Nonpharmacologic treatment of hypertension in diabetes mellitus. Diabetes Care 1991;
    14:449

10. Weidmann P et al Pathogenesis and treatment of hypertension associated with diabetes mellitus.
      Am Heart J 1993; 125:1498

Hypertension in patients with coexisting Cardiovascular Diseases (CVD)

Hypertension is one of the risk factors for atherosclerosis. It also increases the workload of the left ventricle and may lead to left ventricular hypertrophy and left ventricular dysfunction (initially diastolic, subsequently systolic). The increased demand by a hypertrophied ventricle and the reduced supply by atherosclerotic coronary arteries increases the tendency to myocardial ischaemia; and potential complications include myocardial infarction, sudden death, arrhythmias and heart failure. In the presence of cardiovascular disease, blood pressure control becomes important as it may reverse left ventricular hypertrophy, and reduce complications such as heart failure and stroke. Angina and heart failure may improve with control of the hypertension alone.

Coronary Heart Disease (CHD)

The elevated blood pressure should be reduced gradually in patients with CHD. However, more rapid reduction may be needed in patients with acute coronary syndrome. Beta-blockers and calcium channel blockers which do not cause tachycardia may be particularly useful in those with angina. In patients with previous myocardial infarction, beta blockers and ACE inhibitors have been shown to reduce morbidity and mortality

Heart Failure

Diuretics and ACE inhibitors are particularly useful in this group of patients. Combination of hydralazine and isosorbide dinitrate can also reduce blood pressure and improve prognosis. A recent study has shown that losartan, an angiotensin II antagonist may be superior to captopril in the elderly with heart failure. Long acting calcium channel blockers such as amlodipine and felodipine may be considered as alternatives because they do not depress LV function. Beta blockers should not be used except for low dose metoprolol and carvedilol which have been shown to reduce morbidity and mortality.

Left Ventricular Hypertrophy (LVH)

LVH is an independent risk factor for cardiovascular mortality and morbidity. However it is not known if regression of LVH reduces morbidity and mortality. Hypertension, if present, should be treated. All major antihypertenisve drugs have been shown to regress LVH although meta analysis has shown that ACE inhibitors appear to be superior to the other classes in this respect. Weight reduction and dietary sodium restriction also regress LVH.

Peripheral Vascular Disease (PVD)

This includes carotid atherosclerosis,arteriosclerosis obliterans,intermittent claudication and aneurysm.Hypertension is a risk factor for PVD. Treatment of atherogenic risk factors including hypertension may retard progression or induce regression. Caution should be exercised in the use of beta blockers as they may aggravate claudication. ACE inhibitors should be used with caution as they may precipitate deterioration of renal function in those with renal artery stenosis.

Cerebrovascular Disease

Hypertension is an important risk factor for all types of acute cerbrovascular events. Immediately after such an event the blood preassure is elevated. However antihypertensive treatment should be withheld unless the blood pressure is severely elevated. Following an acute cerebral infarction about 85% of patients have mild to moderate hypertension,but by 10-14 days post-stroke,only 30% continue to have hypertension.Hasty treatment to lower the blood preassure may cause more harm due to extension of the ischaemia.Additionally the blood preassure of such patients may be extra sensitive to hypotensive agents and excessive drop may occur to even small doses of hypotensive agents.In acute ischaemic cerobrasvascular infarct elevated blood preassure should not be treated for the first two weeks. If however the diastolic blood preassure is elevated above 120mmHg then it should be treated.

Similiar policy of no hasty hypotensive treatment applies in cerebral haemorrhage.However some patients may come with severe elevation of blood preassure and urgent treatment is necessary. In such a situation the recommended agents are bete blockers and drugs with combined alpha and beta blocking properties. Cerebral vasodialtors such as nitroprusside,hydrallazine and nifedipine are not recommended as they may increase cerebral edema and further elevate intracranial pressure.

In both cerebral infarction and cerebral haemorrhage,the aim should be gradual reduction of BP and patients already on treatment for hypertension should continue their medications. Subsequent to the acute episode, elevated blood pressure should be optimally controlled to prevent recurrent cerebrovascular events.

References

1. Philips,R.A, and Diamond,J.A: Hypertensive Heart Disease. In Fuster,V., Ross,R, and Topol, E.J
    (eds): Atheroclerosis and Coronary Artery Disease. Philadelphia, Lippincott-Raven Publishers,
    1996,pp.275-302

2. Ren,J.-F.,Pancholy, S.B., Iskandrian,A.S,et al.: Doppler echocardiographic evalution of the spectrum
    of left ventricular diastolic dysfunction in essential hypertension. Am.Heart J. 1994,127:906

3. Shepherd, R.F.J., Zachariah, P.K., and Shub, C.: Hypertension and left ventricular diastolic function.
   Mayo Clin. Proc. 1989, 64:1521

4. Houghton J.L., Frank, M.J., Carr, A.A., et al.: Relation among impaired coronary flow reserve, left
    ventricular hypertrophy and thallium perfusion defects in hypertensive patients without obstructive
    coronary artery disease. J. Am. Coll. Cardoil. 1990,15:43

5. Devereux, R.B., Roman, M.J., Ganau A., etal.: Cardiac and arterial hypertriphy and atherosclerosis in
    hypertension. Hypertension,1994,23 (part 1):802

6. Frohlich, E.D., Apstein, C., Chobanian, A.V., et al.: The heart in hypertension. N. Engl. J. Med.
   1992,327:998

7. Ghali, J.K., Liao, Y., Simmons, B., et al.: The prognostic role of LV hypertrophy in patients with or
    without coronary artery disease. Ann. Intern. Med.,1992 117:831

8. Dahlof, B., Pennert, K., and Hansson, L.: Reversal of left ventricular hypertensive patients: A
    metaanalysis of 109 treatment studies. Am. J. Hypertens.,1992, 5:95

9. Habib, G.B., Mann, D.L., and Zoghbi, W.A.: Normalization of cardiac structure and function after
    regression of cardiac hypertrophy. Am. Heart J.,1994, 128:333

10. Alter, M., Friday, G., Lai, S.M., et al.: Hypertension and risk of stroke recurrence. Stroke 1994,
     25:1605

11. O’Connell, J.E., and Gary, C.S.: Treating hypertension after stroke. Br. Med. J.,1994, 308:1523

12. Spence JD, del Maestro RF Hypertension in acute ischaemic strokes. Arch Neurol.1985;42:1000-2

13. Rooper AH, Rockoff MA. Treatment of intracranial hypertension. In: Rooper AH,Kennedy SF,eds.
     Neurological and neurosurgical intensive care. Rockville,Maryland: Aspen Publishers 1988
 

Hypertension in pregnancy

Hypertension in pregnancy is also known as pre-eclampsia, toxemia of pregnancy, eclampsia, hypertension gestosis and pregnancy induced hypertension. It complicates 10-20% of pregnancies and is the major cause of premature birth and perinatal deaths and accounts for 20-33% of all maternal deaths. Hypertension in pregnancy may also result in serious complications to the mother notably placental abruption, disseminated intravascular coagulation, cerebral haemorrhage, hepatic failure and acute renal failure. In view of this, pregnant women with hypertension should be (referred) to the obstetrician.

Diagnostic criteria

Hypertension in pregnancy is defined on the basis of DBP measurement by sphygmomanometry using Phase IV Korotkoff sounds.(There is an argument for using Korotkoff V as it corresponds more closely to intra arterial pressure. However what is probably more important is that clinicians define which end point they are using in each patient to ensure consistency.)

In order to eliminate the hemodynamic changes associated with pregnancy, the blood pressure should be measured with the women lying on their sides at an angle of 15-30 degree to the horizontal. Diagnosis requires two consecutive measurements of DBP = 90 mmHg, four or more hours apart or one measurement of DBP = 100 mmHg.

A variety of classification have been proposed but the most important consideration is the differentiation of hypertension that antedates pregnancy from a pregnancy specific condition which is characterised by poor perfusion of many organs. Hypertension in pregnancy can be divided into four categories.

Preeclampsia-eclampsia

Preeclampsia is characterised by hypertension with proteinuria ( >300 mg/day ) and at times coagulation and/or liver abnormalities. Oedema is no longer used as a criteria. It usually occurs in a woman’s first pregnancy after the 20th. week of gestation and most frequently near to full term.

Preeclampsia may progress rapidly without warning to the convulsive phase known as eclampsia. Differentiating mild from severe preeclampsia based on level of blood pressure and proteinuria, may be dangerously misleading because 25% of women with eclampsia have ‘mild’ disease or minimal elevations of blood pressure before convulsions.

Relevant Investigations
 

Maternal Fetal
Full blood count 
 
Cardiotocograph 
 
Clotting screen Ultrasound 
Serum creatinine 
Serum uric acid
Urinalysis
24 hrs urine protein (if proteinuric)

Management

The decision to use antihypertensives is solely for maternal safety. There is no clear cut fetal benefit of lowering blood pressure and such treatment does not cure or reverse preeclampsia. Therapy for preeclampsia consists of hospitalisation with bed rest, control of BP, seizure prophylaxis when signs of impending eclampsia are present and timely delivery. Pharmacological treatment is indicated if SBP = 160 mm Hg and/or DBP = 100 mm Hg, aiming for a blood pressure of 130/90 mm Hg

Drugs of choice include methyldopa or labetalol. Nifedipine may be considered if the patient is unable to tolerate the above drugs or added if the blood pressure is inadequately controlled. For acute control of severe hypertension intravenous hydrallazine, intravenous labetalol or sublingual nifedipine may be used. Long-term use of beta blockers in pregnancy has been associated with intrauterine growth retardation. Angiotensin converting enzyme inhibitors should be avoided as they are associated with high incidence of intrauterine fetal death.

Delivery remains the only definitive treatment of preeclampsia. Delivery is indicated regardless of gestational age when there are signs of fetal distress, uncontrolled hypertension in the mother, evidence of deteriorating renal or hepatic function, or signs of impending eclampsia (headache, visual disturbance, epigastric pain and hypereflexia). If preeclamsia develops before the fetus is mature, the physician must carefully consider both the maternal and fetal health and decide whether continuation of pregnancy is safe.

Chronic hypertension in pregnancy

Chronic hypertension is defined as hypertension that is present and observed before pregnancy or that is diagnosed before the 20th week of gestation. Hypertension is as defined in the general adult population. Hypertension that is diagnosed for the first time during pregnancy and persists beyond the forty-second day post partum is also classified as chronic hypertension.

Optimum management of a woman with chronic hypertension during pregnancy involves achieving adequate control of her BP plus careful monitoring of maternal and fetal condition. Anti-hypertensive treatment is as for women with preecalmpsia. Women already on other classes of antihypertensive drugs should have their drugs changed accordingly.

Preeclampsia / eclampsia superimposed on chronic hypertension

In patients with preeclampsia/eclampsia superimposed on chronic hypertension, the management is as for preeclampsia and eclampsia.

Transient hypertension

Transient hypertension is the development of elevated BP during the later stage of pregnancy or in the first 24 hours post partum, without other signs of preeclampsia or pre-existing hypertension, and accompanied by a return to normal blood pressure within 10 days of delivery. These patients should be managed as for women with preeclampsia. Long term follow-up of these women are recommended since it is often predictive of eventual development of essential hypertension.

Postpartum considerations

Breast feeding should not be discouraged as most antihypertensives are considered safe for the baby.

Women with postpartum depression and on methyldopa should be offered alternative antihypertensive drugs.  

References

1. Consensus Report. Appendix 138-1, National High Blood Pressure Education Program Working
    Group Report on High Blood Pressure in Pregnancy.

2. ACOG Technical Bulletin/ Hypertension in Pregnancy. No 219. International Journal of O&G 53
   (1996 ) 175-183.

3. WHO Technical Report Series No 862.1996.

4. Redman CWG, Roberts Im. Management of Pre- eclampsia. Lancet 1993 ; 341 : 1451-1454.

5. Girling J, DeSwiet M. Preeclampsia. Update 1996; 338-342.

6. Ramsay MM. Hypertension in Pregnancy. RCOG Yearbook 1995.

7. RCOG Guideline 1996. Management of Eclampsia.

8. Teoh TG, Redman CW. Management of pre-existing disorders in pregnancy : Hypertension.
    Prescriber Journal 1996;36:28-36.

9. Sibai , B.M., Treatment of Hypertension In Pregnant Women. Review Article. Drug Therapy. 1996 ;
    335 : 257-265.

10. Davies , N.J., Hypertension Disorders of Pregnancy for the Trainee. BJOG . 1992 ; 47.No8 : 613-
      618.

11. Scott. A. , Owen, P., Recent Advances in the Aetiology and Management of Pre-eclampsia. BJOG .
     1996 ; 55 : 476-478.

12. Sibai, M., Management of Severe Pre-eclampsia. Maternal and Fetal Medicine and Prenatal
      Diagnosis. Current Opinion in O&G. 1996 ; 8 : 110-113.

13. Mackenzie , F., Greer, I.A., Preventing eclampsia. Current Obstetrics & Gynaecology.
     1996;6: 159-164.

14. RCOG PACE Review No 97/05 (1997). The hypertensive disorder of pregnancy definitions,
     classifications and haematological investigations.

Hypertension in the paediatric patient

Hypertension in children is not as well appreciated as in adults due partly to its lower prevalence. The prevalence of hypertension in children is about 1%. The approach to the management of hypertension in children differs from that in adults in that hypertension in children particularly those younger than 10 years is usually due to secondary causes.

Measurement of Blood Pressure in Children

Measurement of blood pressure is similar to that in adult taking into consideration the different cuff sizes for children of different ages.

BP standards

Growth and maturation are the most powerful determinants of blood pressure in children and adolescents. The 1996 update on the Second Task Force Report on Hypertension in Children has provided normative tables (Tables 9 & 10) of blood pressure based on age and sex adjusted for height percentiles. This is to allow for a more precise classification of blood pressure and avoids mislabelling children at the extremes of growth.

The definition of the distribution of blood pressure will again be based on the Task Force recommendations and they are as follows:
 

Normal BP Systolic and diastolic BP < 90th percentile
High Normal BP Average systolic or diastolic BP 90th-95th percentile
High BP Average systolic or diastolic BP = 95th percentile for at least 3 occasions.

Evaluation

Unlike in adults, secondary causes of hypertension account for a much higher proportion - about 90% in children less than 10 years of age.

History taking in a child with hypertension is similar to that in adults with the exception of neonatal history.It should be remembered that acute and transient increase of blood pressure accompanies many childhood illnesses like acute post-infectious glomerulonephritis and Henoch-Schonlein purpura. The diagnosis of these conditions is usually easily made and management is directed towards treatment of the underlying disease. Treatment of hypertension is usually required only as a temporary measure.

Laboratory Evaluation

This is similar to that of evaluation in the adult hypertensive population.

Treatment

Non-Pharmacologic Management

The principles are as in adults with hypertension and is recommended in all children with hypertension as well as those with blood pressure in the 90th to 95th percentile.

Pharmacologic Management

The goal of drug therapy is to reduce blood pressure to lower than 95th percentile.

The anti-hypertensive drugs for the treatment of chronic hypertension in children are as in Table 11.

Table 11 Antihypertensive Drugs for Therapy of Chronic Hypertension in Children
 

Drug  Dose, mg/kg/d 
Initial
Maximum   Dosing Interval 
a /b blockers 
Labetalol
1  3 Every 6-12 h 
a blockers 
Prazosin
0.05-0.1  0.5 Every 6-8 h 
a blockers 
Atenolol 
Propranolol
1 
1
 8  
 8 
Every 12-24 h 
Every 6-12 h 
Centrally-acting drugs  
Clonidine 
0.05-0.1*  0.5-6* Every 6 h 
Calcium channel blockers  
Nifedipine
0.25    3 Every 4-6 h
ACE Inhibitors  
Captopril 
   Children 
   Neonates 
Enalapril 
1.5 
0.03-0.15 
0.15 
6 
2 
Not established
Every 8 h 
Every 8-24 h 
Every 12-24 h 
Diuretics 
Bumetanide 
Frusemide 
Hydrochlorothiazide 
Spironolactone 
Triamterene 
0.02-0.05 
1 
1 
1 
2
0.3 
12 
2-3 
3 
3
Every 4-12 h 
Every 4-12 h 
Every 4-12 h 
Every 6-12 h 
Every 6-12 h
Direct Vasodilators 
Hydrazine 
Minoxidil
0.75 
0.1-0.2
7.5 
1
Every 6 h 
Every 12 h

 
* Total initial and daily dose in mg

Adapted from Update on the 1987 Task Force Report on High Blood Pressure in Children and Adolescents (1996).

Drug therapy should be individualised as in the general recommendations for adults. Acute hypertension resulting from conditions like acute glomerulonephritis and head injuries may result in rapid and symptomatic increase in blood pressure. Blood pressure should be quickly reduced with drugs with a rapid onset of action. When a child or adolescent believed to have essential hypertension requires more than two anti-hypertensive drugs, the aetiology of hypertension needs to be reassessed.

The drugs available for treatment of hypertensive emergencies in children are as in Table 12 

Table 12 Antihypertensive Drug Therapy for Hypertensive Emergencies in Children
 
 

Drug Dose*
Nifedipine 0.25-0.5 mg/kg oral prn; may be repeated two times if no response 
Sodium nitroprusside 0.5-1 m g/kg/dose IV; may be increased stepwise to 8m g/kg/min maximum 
Labetalol 0.2-1 mg/kg/dose IV; may be increase incrementally to 1 mg/kg/dose until response achieved; 0.25-2 mg/kg/h maintaince, either bolus or IV infusion 
Diazoxide 1-5 mg/kg/dose IV bolus upto maximum of 150 mg/kg
Hydralazine 0.2-0.4 mg/kg IV prn; may be repeated two times if no response
Minoxidil 0.1-0.2 mg/kg oral

* Total initial and daily dose in mg.

Table 9 Blood Pressure Levels for the 90th and 95th Percentiles of Blood Pressure for Boys Aged I to 17 Year by Percentiles of Height

*Blood Pressure Percentile was determined by a single measurement. +Height percentile was determined by standard growth curves.

Table 10 Blood Pressure Levels for the 90th and 95th Percentiles of Blood Pressure for Girls
Aged 1 to 17 Years by Percentiles of Height

References
 
1.  Rames Lk, Clarke WR, Conner WE et al. Normal blood pressures and the evaluation of sustained
     blood pressure elevation in childhood: the Muscatine Study. Pediatrics 1978;  61:45

2.  Sinaiko AR, Gomez-Marin O, Prineas RI. Prevalence of “significant” hypertension in junior high
     school-aged children: the Children and Adolescent Blood Pressure Program. J Pediatr 1989; 114:664

3.  Task Force on Blood Pressure Control in Children. Report of the Second Task Force on Blood
     Pressure Control in Children - 1987. Pediatrics 1987; 79:1

4.  Houtman PN, Dillon MJ. Routine measurement of blood pressure in school children. Arch Dis Child
    1991; 66:567

5.  Gillman MW, Cook NR, Rosner B, Evans DA, et al Identifying children at high risk for the
     development of essential hypertension. J Pediatr 1993; 122:837

6.  Lauer RM, Clarke WR, Mahoney LT, Witt J. Childhood predictors for high adult blood pressure - the
     Muscatine Study. Pediatr Clin North Am. 1993; 40:23

7.  National High Blood Pressure Education Program Working Group on Hypertension Control in
     Children and Adolescents. Update on the 1987 Task Force Report on High Blood Pressure in
     Children and Adolescents: A working Group Report from the National High Blood Pressure
     Education Program. Pediatrics 1996; 98:649

8.  Sadowski RH, Falkner B. Hypertension in Pediatric Patients . Am J Kidney Dis. 1996; 27:305
 

Hypertension in the Elderly

Hypertension in the elderly (i.e. over age 65) is an increasingly important public health concern. Hypertension in the elderly is a major risk factor for stroke, cardiovascular disease and death from cardiovascular causes. These risks are magnified in the elderly, probably because of the higher prevalence of associated cardiovascular risk factors and overall higher likelihood of cardiovascular events.

The definition for hypertension in the general adult population applies. Increased systolic blood pressure associated with ageing is not benign; systolic hypertension is a more potent risk factor than increases in diastolic pressure. Several trials have shown that treatment of hypertension in the elderly upto the age of 84 years reduces cardiovascular morbidity and mortality.

Detection and Evaluation

Recommendations for blood pressure measurement in elderly patients are similar to those for the general population. Postural hypotension is a common problem in the elderly. Therefore, blood pressure should be measured in both supine and standing positions. If there is a significant postural drop the standing blood pressure is used to guide treatment decisions. Evaluation of elderly patients with hypertension should not differ from that of younger adult patients. Particular attention should be paid to detect atheromatous renal artery disease as the cause of secondary hypertension.

Treatment

Target blood pressure

Goals for blood pressure reduction in the elderly differ from those in the younger adult population. In the elderly, although the target diastolic pressure is the same, the target systolic pressure may be higher. For those with SBP between 160 and 180 mm Hg, the pressure should be reduced by 20 mmHg. For those with SBP >180 mm Hg, the target pressure should be <160 mm Hg.

Non-Pharmacological Management

Attempts at lifestyle modifications while beneficial may not be practical in the elderly. However sodium reduction may be especially effective in the elderly because of their greater sensitivity to sodium intake.

Pharmacological Management

Large clinical trials have shown that diuretics and beta-blockers are both very effective in lowering blood pressure in the elderly. Both have been shown to reduce the incidence of stroke but only diuretics are effective in reducing cardiovascular morbidity and mortality. Several trials using calcium channel blockers have shown benefits particularly in stroke reduction in elderly hypertensives. ACE inhibitors are the drugs of choice for those with left ventricular systolic dysfunction, post myocardial infarction and those with concomitant diabetes mellitus.

Special considerations in the treatment of elderly patients

In the treatment of hypertension in the elderly, certain considerations should be taken into account. The elderly are more vulnerable to side-effects and treatment should "start low and go slow". In order to maximise compliance, the drug regime should be as simple as possible.

References

1. Joint National Committee on Detection, Evaluation and Treatment of High Blood Pressure. The fifth
    report of the Joint National Committee on Detection, Evaluation and Treatment of High Blood
    Pressure. Arch. Intern. Med. 1993; 153: 154-83.

2. Mann SJ. Systolic hypertension in the elderly. Arch Intern. Med. 1992; 152: 1977-84.

3. MRC Working Party. Medical Research Council Trial of Treatment of Hypertension in Older Adults:
    principal results. BMJ 1992; 304: 405-12.

4. Dahlof B, Lindholm LH, Hannson L, Schersten B, Ekbom T, Wester PO. Morbidity and mortality in
    the Swedish Trail in Old Patients with Hypertension (STOP-Hypertension). Lancet 1991; 338:
    1281-85.

5.The Systolic Hypertension in the Elderly Programme (SHEP) Co-operative
   Research Group. Prevention of stroke by antihypertensive drug treatment in older persons with
   isolated systolic hypertension: final results of SHEP. JAMA 1991; 265: 3255-64.

6. Amery A, Birkenhager W, Brixko P, et al. Mortality and morbidity results from the European Working
   Party on High Blood Pressure in the Elderly Trial. Lancet 1985; I:1349-54.

7. Weinberger MH, Fineberg NS. Sodium and volume sensitivity of blood pressure: age and pressure
    change over time. Hypertension 1991; 18:67-71.

8. Materson BJ, Reda DJ, Cushamn WC, et al. Single-drug therapy for hypertension in men: a
    comparison of six antihypertensive agents with placebo. N Engl J Med 1993; 328: 914-21.
 

Appendix

Classes of Anti-hypertensive Drugs

Diuretics

Diuretics have been widely used and have been shown to be effective in the prevention of cardiovascular morbidity and mortality. Diuretics are inexpensive and are particularly valuable as adjunctive treatment to enhance the effectiveness of many anti-hypertensive drugs.

Diuretics may cause a variety of unwanted metabolic effects (potassium depletion, hyperuricaemia and reduced glucose tolerance) and impotence that can be reduced if the dose is kept as low as possible.

Potassium sparing diuretics are less effective anti-hypertensive agents when used on their own. However, they may be combined with other groups of diuretics to reduce potassium loss. Total daily doses for commonly used diuretic:
 

Starting Dose Maximum Dose 
Hydrochlorothiazide 12.5 mg 100mg 
Indapamide  2.5 mg  2.5 mg 
Chlorothiazide 125 mg 1000 mg 

Beta-blockers

Beta-blockers are widely and effectively used in the treatment of hypertension. Numerous beta-blockers are available, some with cardioselective properties, others with partial agonist activity, and others with alpha-blocking and vasodilator properties. They are particularly useful in hypertensive patients with effort angina, tachyarrhythmias or previous myocardial infarction where they have been shown to reduce cardiovascular morbidity and mortality.

They should be avoided in patients with obstructive airways disease, heart failure and peripheral vascular disease. However, metoprolol and carvedilol may be used with caution in heart failure. Beta-blockers may also have unfavorable effects in patients with dyslipidaemia, impaired glucose tolerance or diabetes mellitus, as well as in athletes.

Total daily doses of commonly used beta-blockers:
 
 

Starting Dose Maximum Dose 
Atenolol 25 mg 100 mg 
Propranolol 40 mg 320 mg 
Metoprolol 50 mg 200 mg 
Bisoprolol 5 mg 20 mg 
Acebutolol 400 mg 800 mg 
Oxprenolol 80 mg 160 mg 
Carvedilol 25 mg 50 mg 

 

ACE Inhibitors

ACE inhibitors are effective in lowering blood pressure. They are generally well tolerated and do not have adverse effects on lipid and glucose metabolism. Their safety profile is good. ACE inhibitors have been shown to reduce mortality and morbidity in patients with congestive heart failure and those post-myocardial infarction particularly those with reduced ejection fraction. In diabetic nephropathy, ACE inhibitors have been shown to reduce proteinuria and slow the progression of renal disease. ACE inhibitors have also been shown to have an antiatherosclerotic effect.

Adverse effects include cough and, rarely, angioedema. In patients with renovascular disease or renal impairment, deterioration in renal function may occur. ACE inhibitors may increase fetal and neonatal mortality and therefore are contraindicated in pregnancy and should be avoided in those planning pregnancy.

Total daily doses of commonly used drugs:
 

Starting Dose Maximum Dose
Captopril 25 mg  450 mg 
Enalapril 10 mg 40 mg 
Lisinopril 10 mg 40 mg 
Perindopril 4 mg 8 mg 
Quinapril  10 mg 40 mg 
Fosinopril 10 mg 40 mg 

 

Calcium Channel Blockers

There are three major classes of calcium channel blockers (phenylalkylamines, dihydropyridines and benzothiazepines) with different characteristics and all are effective in lowering blood pressure. With few exceptions, they have no undesirable metabolic effects and their safety profile in hypertension appears good. It has been reported that certain calcium channel blockers reduce cerebrovascular events. In patients with atherosclerotic arterial disease, calcium channel blockers may reduce the development of new plaques.

Side effects include initial tachycardia, headache, flushing and ankle oedema. Unlike other calcium channel blockers, verapamil may reduce heart rate and should not be used with beta-blockers. In the light of recent limited reports, short acting nifedipine should not be used in doses greater then 60 mg per day in the treatment of hypertension.

Total daily doses of commonly used calcium channel blockers:
 

Starting Dose  Maximum Dose 
Nifedipine 30 mg 60 mg 
Nicardipine 30 mg 60 mg 
Isradipine 5 mg 10 mg
Felodipine 2.5 mg 10 mg
Amlodipine 5 mg 10 mg 
Lacidipine 4 mg 6 mg 
Diltiazem 90 mg 480 mg 
Verapamil 240 mg 480 mg 

   

Peripheral Alpha1-blockers

This class of drugs effectively reduces blood pressure. They have beneficial effects on lipid and glucose metabolism. Postural hypotension is a potential problem particularly in the elderly.

Total daily dose of commonly used drug:
 

Starting Dose  Maximum Dose 
Prazosin 1 mg 20 mg 

 

Angiotensin II Antagonists

Angiotensin II antagonists are a new group of anti-hypertensive drugs. They are effective in lowering blood pressure. Unlike ACE inhibitors cough does not appear to be a problem with their use. As with ACE inhibitors, they are contraindicated in pregnancy.A recent study showed losartan (angiotensin II antagonist) to be superior to captopril in elderly patients with heart failure.

Total daily dose of commonly used drug:
 

Starting Dose Maximum Dose 
Losartan 50 mg 100 mg 

 

Centrally Acting Drugs

Centrally acting drugs are effective anti-hypertensive agents and have been used for many years. Methyldopa has been proven to reduce cardiovascular events in clinical studies. Methyldopa remains an important and safe agent in the treatment of hypertension in pregnancy.

Adverse effects of centrally acting drugs include postural hypotension, drowsiness, mood change and impotence.

Total daily dose of commonly used drug:
 

Starting Dose Maximum Dose 
Methyldopa 500 mg 3000 mg

 

Direct Vasodilators

Direct vasodilators are effective in lowering blood pressure. Side-effects such as tachycardia, headache, and sodium and water retention may limit their usefulness as monotherapy.
 

Choice of Anti-Hypertensive drugs in patients with concomitant disease
 

Concomitant 
Disease
Diuretics Beta-blockers ACE inhibitors Calcium channel blockers Peripheral alpha1-blockers Angiotensin II antagonists      
Diabetes mellitus care needed care needed yes * yes yes yes      
Gout No yes  yes yes yes yes/no      
Dyslipidaemia care needed care needed yes yes yes yes      
Ischaemic heart  
Disease
yes yes * yes yes yes yes      
Heart failure yes care needed yes* care needed yes yes      
Asthma yes  no yes yes yes yes      
Peripheral vascular disease yes care needed care needed yes yes yes      
Renal impairment yes yes care 
needed
yes yes care 
needed
     
Renal artery stenosis yes yes care needed yes yes care needed      
Elderly with no co-morbid conditions yes* yes* yes yes* yes yes      

* Drug of choice, (please refer to appendix)